The present invention relates to a compressor and more particularly, to the shut-down control of an electrically driven motor compressor in which vibration of the compressor components and motor due to inertia force during operation is reduced at the time of stopping thereby decreasing vibrations and noise of the compressor.
Commonly, a motor compressor, for example, a hermetically sealed motor compressor which includes a motor-compressor unit spring-suspended within a housing is widely employed as a cooling medium compressor or air compressor for the refrigeration circuit in refrigerators, air-conditioners and the like, and also as a reciprocating type compressor for similar purposes.
For the operation of shutting down a motor compressor of the above described type, it has been a general practice to cut off the power supply depending on the necessity. In such shut-down, however, it is known that extremely large vibrations tend to take place, frequently giving rise to abnormal noises, mainly due to compressor components which are supported by spring means striking against surrounding structures in the housing.
Accordingly, the designing a vibration-absorbing spring system for such conventional compressors, the vibration attenuating effect thereof during steady operation of the compressor is sacrificed to a certain extent, with various countermeasures being taken into account, such as an increase of the spring constant for preventing large vibrations at the time of shut-down or providing sufficient space to prevent the compressor components from striking against the surrounding structures, thus resulting in a higher cost and larger size of the motor compressor would otherwise be than necessary.